Many philosophers endorse a truth-insensitivity hypothesis: certain core, philosophically important evaluative properties of a belief are insensitive to whether it is true. For example, if two possible agents believe the same proposition for the same reason, then either both are justified or neither is. This does not change if it turns out that only one of the two agents has a true belief. Epitomizing this line of thought are thought experiments about radically deceived “brains in vats.”
Proponents claim that the truth-insensitivity hypothesis is extremely intuitive and appealing pre-theoretically — we have an “overpowering inclination” to think that it’s true (Richard Fumerton). To deny the truth-insensitivity hypothesis has been labelled “extraordinary” and “dissident” (Earl Conee). However, other philosophers claim that exactly the opposite is true: the truth-insensitivity hypothesis itself is counterintuitive and violates commonsense. The appeal of truth-insensitive epistemology, they claim, is limited to narrow circles within “the professional philosophical community” (Jonathan Sutton).
In a paper forthcoming in Philosophy and Phenomenological Research, I investigated which side of this debate is correct. Proponents of the truth-insensitivity hypothesis illustrate their view’s plausibility with pairs of thought experiments. These pairs include mundane cases and fanciful “brain-in-a-vat” scenarios. I tested both sorts of cases.
Across three experiments (N = 1262), the results were absolutely clear:
Ordinary evaluations of belief were deeply truth-sensitive. There was a consistent pattern whereby belief and evidence were judged much more favorably when the proposition in question was true rather than false. This was true across multiple narrative contexts and for evaluations elicited with a wide range of normative vocabulary (e.g. justification, evidence, rationality, reasonableness, responsibility, and what an agent should believe). It was true when people judged the pairs of cases separately (between-subjects) and when they judged the cases simultaneously (within-subjects). The basic finding appears to be very robust.
I find it fascinating that commonsense cuts so strongly against truth-insensitivity. I also find it somewhat disconcerting in light of the way introductory texts tend to treat the matter. For instance, how many epistemology students in recent decades have had their own judgments marginalized or contradicted by what “we” find intuitively compelling, and to what effect? That seems like a question researchers in the field should take seriously.
(x-posted at the x-blog)